I'm always on the lookout as most true collectors are. I have seven from Niagara, but only a couple listed in the library. Need to get that updated. I think there are some really early ones that may be rare. Not sure about a following of collectors seeking them though. I like them, but think most collectors look for the Canadian side of the border. Thanks for the reply.
Have attached a picture of one with an upside down plate mold.